(a) Field of the Invention
The invention relates to a trocar sleeve for guiding endoscopes and operation instruments which can be exchanged for a trocar, it being possible for the tube of the trocar sleeve to be connected proximally to a handle part and to be closed in a gas-tight manner.
(b) Description of the Prior Art
Known trocar sleeves have conventional ball valves, trumpet valves or solenoid valves to close the central tube channel of the trocar sleeve before introducing or after removing a guided endoscope, an auxiliary instrument or the like, in a gas-tight manner. Trocar sleeves of this type are disclosed in the following references: German Gebrauchsmuster Nos. 70 04 051, 72 20 273, 74 30 345, 77 35 963 and 77 36 389.
A disadvantage of known trocar sleeves is that the closing element is biased by a spring, as a result of which the endoscopes or instruments are engaged at their outer surfaces and therefore their free movement and guidance is braked or otherwise restricted. Engagement of the instruments may have a disadvantageous effect on their operability or may even render the instruments unusable. Furthermore, since trocar sleeves generally consist of metal, this may have an interfering effect when taking X-rays, since organs of the body may be covered by the sleeve. Also, when changing the instrument, loss of gas may occur during introduction or removal.
The principal objects of the invention are to avoid the abovementioned disadvantages of known trocar sleeves, to be able to introduce endoscopes and instruments through the trocar sleeve into the body cavity unhindered by friction and to be able to use instruments and endoscopes of different diameter or cross-sectional profile.